An antenna is an essential device for transmitting and receiving a radio wave in wireless communication. The length of the antenna is proportional to the wavelength of the radio wave. The wavelength is expressed in a formula λ=c/f, where λ is a wavelength, f is a frequency, and c is a constant. Accordingly, the length of the antenna is inversely proportional to the frequency.
An antenna of a mobile terminal must be long enough to receive a digital broadcast signal in a low frequency band. In a conventional mobile terminal, a whip antenna is used to receive a digital broadcast signal. The whip antenna is retracted into the mobile terminal when not in use. The whip antenna of the mobile terminal is extended outwards when the mobile terminal is used to receive a digital broadcast signal. When receiving a digital broadcast signal, the whip antenna is extended to the outside of the mobile terminal and, thereby, becomes a correct length for the frequency of a digital broadcast signal. However, if the whip antenna is not extended outwards when receiving a broadcast signal, reception of the broadcast signal is unstable because the length of the whip antenna does not match the frequency of the digital broadcast signal.
Further, the whip antenna may be damaged, and its connection parts may be easily worn by repeated extension and retraction.